The invention relates to the deposition of a hardenable fluid or viscous material. It concerns, first, a device for measuring and regulating the flow rate of a fluid or viscous material. The device comprises an opening for feeding fluid into a cavity delimited by walls. The cavity contains means for controlling the transport of the material to an outlet orifice in the cavity.
The technique used to regulate the flow rate of a fluid is known (see, for example, French Patents Nos. FR 1 074 689 and FR 1 323 988). These known flow rate-measurement and regulating devices do not permit the deposition of a hardenable fluid material on an object. In addition, these known devices are bulky and heavy, thereby adversely affecting the use or shipment thereof by a human operator or robotic manipulator, and, accordingly, the deposition of the material along a three-dimensional curve incorporating a complex shape.
Furthermore, it is not possible to connect these known devices, for example using flexible tubing, to a mobile deposition nozzle, because the hardenable fluid materials are often expandable and compressive when subjected to pressure.
In this situation, the tube expands due to pressure variations, with the result that the flow rate of the pump no longer corresponds to the flow rate of the nozzle.
The invention is intended to solve these difficulties. To this end, the device according to The invention has an outlet orifice which empties into a deposition nozzle made integral with the walls of a cavity.
To regulate flow rate continuously, the fluid-propulsion mechanism is a gear assembly in which the axis of each pinion is substantially perpendicular to the axis of the outlet orifice of the cavity.
The fluid-propulsion mechanism is actuated by a motor, in particular an electric motor.
Flow rate is proportional to the rotation of the gears, and thus, to the rotation of the electric motor, the controlled rotation of which allows measurement of the flow rate.
To obtain a pressure differential approaching zero, i.e., a high degree of adjustment precision without internal material leakage, the device incorporates two pressure bleeds, one of which is up-line, and the other down-line, from the cavity.
Reduction of this internal leakage increases volumetric efficiency and prevents overheating that could adversely affect the material.
In order to keep viscosity within a narrow range and to handle the material, the cavity walls generate heat, for example using cartridges housed in holes, and a heating plate is added to the device, or else a nozzle-, motor-, and/or manipulator-positioning heating element is attached to the device according to the invention.
The nozzle comprises an extrusion orifice incorporating, at the end thereof, an adjustable opening/closing valve, thereby making it possible to obtain a "zero" cavity, that is, a cavity without material in contact with the outside, which could otherwise harden and clog the nozzle.
The invention also concerns a manipulator, in particular a robot of the type incorporating a mobile body on which is mounted a jointed arm having, at its end, a revolving wrist attached to a fluid-deposition gun, the gun comprising an opening for fluid-feed to a cavity delimited by at least one wall, the cavity housing gears for fluid propulsion to an outlet orifice, in which the gun corresponds to the aforementioned device.
The invention further relates to a procedure for deposition of a hardenable fluid or viscous material, deposition occurring by means of the flow of the material into a nozzle, wherein the material is heated, then the flow rate of the material is measured and adjusted, thereby allowing variation of the outlet flow rate of the material during a single deposition operation. Accordingly, if the manipulator slows, it is possible to adjust the flow rate in order to preserve the same linear weight of the deposited product.